LiteX Wishbone Slave

led_gpio.py

from migen import *

from pathlib import Path

class LedGpio(Module):
    def __init__(self, platform, led: Signal):
        source = Path(__file__).parent / "led_gpio.v"
        platform.add_source(source)

        self.adr = Signal(32)
        self.dat_w = Signal(32)
        self.dat_r = Signal(32)
        self.sel = Signal(4)
        self.cyc = Signal()
        self.stb = Signal()
        self.ack = Signal()
        self.we = Signal()
        self.cti = Signal(3)
        self.bte = Signal(2)
        self.err = Signal()

        # Needs to be added in self.specials
        self.specials += Instance("led_gpio",
            p_DATA_WIDTH=32,
            p_ADR_WIDTH=32,
            p_SEL_WIDTH=4,
            i_clk=ClockSignal(),
            i_rst=ResetSignal(),
            i_adr=self.adr,
            i_dat_w=self.dat_w,
            o_dat_r=self.dat_r,
            i_sel=self.sel,
            i_cyc=self.cyc,
            i_stb=self.stb,
            o_ack=self.ack,
            i_we=self.we,
            i_cti=self.cti,
            i_bte=self.bte,
            o_err=self.err,
            o_led=led
        )

soc.py

class BaseSoC(SoCCore):
    def __init__(self, **kwargs):
        # boilerplate from colorlight i5 goes here
        
        # LED blinky thing
        wb_interface = wishbone.Interface()
        led = platform.request("user_led_n")
        self.submodules.led = led = led_gpio.LedGpio(platform, led)
        wb_interface.connect_to_pads(led, mode="slave")

        self.add_memory_region("led_gpio", 0x8F000000, 0x1000, type="dawda")
        self.add_wb_slave(0x8F000000, wb_interface, 0x1000)

        # vague attempt based on colorlight i5 target, didn't suspect it would make much of a difference
        #region = SoCRegion(origin=0x8F000000, size=0x1000, cached=False)
        #self.bus.add_slave(name="led_gpio", slave=wb_interface, region=region)